The prior art has been more concerned with the problems relating to accommodation of different display devices on the same system than the lack of uniformity of screens between application programs. The prior art has also addressed the problems which arise when new displays are added to an old system.
Exemplary of the prior art is U.S. Pat. No. 4,586,158 which describes a mapping service which effects the interface between the application program and the physical presentation of the information on the display screen. Simply stated, the program logic of the mapping service transforms the data represented in the format of the application program into another format based on a specified set of rules. There is no suggestion as to how displayed data common to more than one application program could be shared. This system operates to change the stored data in accordance with a set of predetermined rules, and there is no suggestion as to how the data can be specified so as to be uniformly usable by all the display devices and screens without the need for reformatting.